Advice for Travel/Living Abroad...

Dear Experienced Travelers and Expats of InterNations,

On April 1st my fiancee and I will be heading to Europe, current destination is Vienna.

We may live abroad for Protected content . At this time neither of us will enter Europe on a work Visa or a student Visa... knowing the 90 day limitation by country for "tourists" we may have to pick up and move several times, but we don't have a plan that far in advance.

We are going to get our airline tickets soon and I have a question:

Is it necessary for us to purchase a ROUND-TRIP ticket to avoid problems entering the country at customs/immigration checkpoint in the airport?

Ideally, we would be able to fly to Vienna on our Passports, then see what happens... maybe we find an opportunity to stay, or maybe we head to Spain, etc...

I am a US citizen, my fiancee is a Venezuelan citizen. According to official sites, we can both travel to Austria without a Visa, only with our Passports.

Thank you for any advice...

Michael